Comet ISON: Hope or Hype?

Word is out on the street, or at least in the astronomical community. Comet ISON may not be performing up to expectations.

The comet, hailed by the media as a possible “Once a century comet” that will shine “Brighter than the Full Moon” has made its appearance out from behind the Sun, and initial reports from ground-based amateurs has found its performance a bit lackluster.

The latest word on Comet C/2012 S1 ISON’s possible demise comes from a recent report online via Sky & Telescope by Arizona-based amateur astronomer Bruce Gary. Gary recovered ISON on August 12th, low in the dawn sky using an 11-inch reflecting telescope and estimated its current magnitude at just under +14, a full 2 magnitudes or six times fainter than predicted.

But are calls declaring ISON’s downfall warranted?

We’ve written about the prospects for this sungrazing comet since its initial discovery late last year. We’ve also warned of the possibility that ISON may go the way of Comet Kohoutek in the 1970’s or comet Elenin, both comets that fizzled after much media fanfare.

Comet hunter David Levy once said “comets are like cats; they have tails and do exactly what they want,” and ISON seems to be planning on living up to that expectation.

A recent study out of the Physics & Astrophysics Computation Group at the University of Antioquia in Medellin, Columbia shows just how on edge the media is when it comes to this comet. When researchers sited a “sudden death” imminent for ISON, Twitter and science blogs trumpeted ISON’s demise. One of the few voices of reason was Nancy Atkinson at Universe Today, who urged caution when attempting to divine ISON’s future behavior.

We plan on playing the long game when it comes to ISON. We interviewed veteran comet observer John Bortle earlier this year on prospects for observing comet ISON on its current passage.

Unfortunately, we suspect that the “ISON has failed” posts will become more prominent as we head into the Fall. ISON won’t pass the +10th magnitude threshold until around late September, when it will become a reasonable object for binoculars under a dark sky.

ISON will pass 10.8 million kilometres from the planet Mars on October 1st, and may become the first comet observed from the surface of another world if NASA’s Mars Science Laboratory Curiosity can catch sight of it from the surface of the Red Planet.

ISON’s “greatness” pivots on one key factor; its survival past perihelion. ISON will pass only 1.1 million kilometres from the surface of the Sun on November 28th. This is when it will reach its peak projected brightness, but it will also be lost in the glare of the Sun.

Things could get really exciting if ISON survives its perihelion passage. Then we’ll have a fine comet with a splendid tail gracing the dawn skies for northern hemisphere observers in the weeks leading up to Christmas.

Comet Ikeya-Seki was the last sungrazer to put on a fine performance for northern hemisphere viewers in 1965. More recently, Comet Lovejoy survived a 140,000 kilometre passage above the dazzling photosphere of the Sun in 2011 to become a fine object for southern hemisphere viewers.

We’ve also had great showings from such memorable comets as C/2006 P1 McNaught in 2007, and Hale-Bopp & Hyakutake in 1996 & 1997.

That’s our synopsis on where we stand for potential prospects for this fascinating but possibly fickle comet. We would take those early reports of “ISON’s demise” with a grain of salt, knowing the roller coaster ride that is the modern media.

Science journalist, astronomy specialist, educator. Retired from the USAF in 2007 and am now a science teacher and freelance science writer. Am out stargazing on every clear night and hope to add science... read more fiction writer to my resume!View author's profile